Keeping the Lines of Communication Open
Condensate
Polishing: Essential
Technology for
Combined Cycle Gas
Turbine Plants
Condensate Polishing Protects
Assets, Stabilizes Cycle Chemistry
and Optimizes Operation
W
ith natural gas at historic
low prices and a forecast
abundance in the near
future, utilities are rapidly planning and
constructing combined cycle gas turbine
(CCGT) plants. Other factors push the
CCGT growth curve as well. “Renewable
energy is becoming a significant source
in several geographies – the United
States and Europe, for example – and
CCGT flexibility facilitates that emerging
energy mix on cloudy, calm days, or at
night,” says Anand Harohalli, Graver
Technologies’ director of business
development. They’re also increasingly
tapped for affordable base load – the
plants are economical to site and build,
too – as coal-fired plants face constraints
like environmental regulation and aging
infrastructure.
Significant new CCGT capacity is
under development in a number of areas,
with industry watchers labeling much of it
“early phase.” That’s the time to plan an
essential element of CCGT construction:
condensate polishing (CP). Many historic
CCGTs, planned and constructed as
peaking units with low utilization rates,
lack CP systems; about six percent of
existing U.S. CCGT facilities have them,
for example. But high usage patterns and
CCGTs constituted about 56 percent of
capacity additions in the United States
alone between 2002 and 2012.
Source: Power Magazine, October 1, 2012
|
SUMME R 2 0 1 3
frequent cycling without CP cause serious
consequences: accelerated corrosion,
inefficient operations, higher insurance
rates and prohibitive future expenditures
to replace damaged equipment.
“CP systems – whether specced in
during development or retrofitted to an
existing plant – are vital to long-term
performance,” says Gil Royal, Graver
Technologies’ North American Utility
sales manager, who says that air-cooled
condenser systems, once through steam
generators or those with more than
100 annual startups definitely need
condensate polishing. “CP safe-guards
assets, stabilizes cycle chemistry, protects
the steam turbine and HRSG, and
optimizes operations.”
Graver Water Systems and Graver
Technologies – Marmon Group
companies owned by Berkshire
Hathaway – have pioneered CP and
high purity water treatment for decades.
Together they make the world’s most
complete solutions for CCGT CP and
filtration systems. The two companies offer
the equipment, technology, products,
experience and capabilities to manage
CP and filtration needs at any CCGT
plant. “Facility size, footprint, location,
equipment type, flow rates, unusual
chemistry profiles, different condensers –
we create CP systems tailored to handle
any circumstance,” says Bob Applegate,
Graver Water Systems sales manager.
This historic 1963 photograph shows one of
the first two Powdex® systems ever installed.
Two 48-inch diameter vessels treated 2,000
gpm of high purity condensate at a 325 MW
U.S. power plant.
Utilities are currently planning
83,831 MW of CCGT capacity in the
United States. About 25 percent is in
the earliest “announced” stage of
development while 34 percent is in
early development. About 11,000 MW
of CCGT capacity is under construction.
What type of CP system best suits
CCGT CP needs? See below for a
review of several alternatives: precoat
demineralizers, disposable and
backwashable filtration, and deep
bed ion exchange systems. 
Precoat Filter
Demineralizers:
The Preferred CP
Choice
Efficiently Removing Suspended
and Dissolved Contaminants with
Low Maintenance Systems
G
raver Water and Graver
Technologies invented the
precoat filter demineralizer
technology more than 50 years ago,
installing the first Powdex® system.
For most CCGT plants, a precoat filter
demineralizer is the best solution for
a number of reasons:
Effective, nearly turnkey custom systems
stand the test of time: Graver Water’s
complete custom Powdex system includes
skid-mounting, all vessels, the required
number of precoat septa, piping, stateof-the-art process controls, and the ion
exchange resins necessary for system
startup. This equipment demonstrates
reliable operation and uniform flow
pattern through mechanically strong
septa – typically needing replacement at
long intervals of five to seven years – that
withstand repeated backwashing.
2 | Powerline
Further,these systems often handle high
flow rates up to 6,000 gallons per
minute per vessel.
Innovative products remove a wide range
of soluble and suspended contaminants:
Graver Technologies’ ion exchange
products combine ion exchange and
suspended solids filtration in one process.
They remove iron, copper silica, activated
corrosion
products and
salts, whether
contaminants
are soluble or
suspended.
Graver
chooses from
an extensive line of Powdex® product
choices – including Ecodex® cation and
anion exchange
resins uniquely
blended with a
cellulose fiber filter
aid, and Powdex®
Premix anion and
cation exchange
resins – to suit any
CCGT CP system
parameters or
needs: chemistry, flow rate, particulate
type and more. Resin selections are easily
modified to handle different condensate
chemistries including unusual heavy
metals.
Equipment and products are designed
to work together: Graver Water and
Graver Technologies designed the stateof-the-art equipment and ion exchange
products in tandem for optimum
performance and durability. “Competitors
offer septa and ion exchange products
for Powdex equipment but they are
trying to accommodate a system they
didn’t design. That may compromise
performance,” remarks Charlie Mosser,
Graver Technologies’ technical service
manager.
Equipment and products are compact
and easy to use: Skid-mounted for quick
installation and rapid start up, Powdex
is easily specced into facility designs
and retrofitted into compact spaces at
existing sites.
Preferred over standalone filtration or deep
bed ion exchange systems, state-of-the-art
Powdex precoat filter demineralizers suit
new or retrofit installations.
Low maintenance is easily handled by
limited personnel: CCGTs help utilities
reduce manpower and precoat filter
demineralizers require minimal upkeep.
There is no need for dosing chemicals.
Further, easy-to-handle product bags
are simply opened and poured into the
system while backwashing procedures
are nearly automatic. If condensate
chemistry changes, resin adjustments are
easily accomplished. Precoat septa are
typically replaced at very long intervals
of five to seven years.
Graver continues intensive CP
innovation: Graver Technologies and
Graver Water continue to collaborate on
further improving Powdex systems and
products for CCGT plants. “We think it’s
the best system on the market for both
ion exchange and filtration,” Royal says,
“created by companies who specialize
in CP, commit significant R & D resources
to it and work closely together on system
design, installation and service.”
To further discuss the advantages of
customized precoat demineralizer
systems for CCGT CP needs, please
contact your Graver representative. 
“Our Powdex system allows us to
better control water chemistry
parameters after shutdowns, which
permits shorter startup periods.”
– Plant manager, 900 MW CCGT Facility
Disposable and
Backwashable Filters:
Cost-Effective for
Short-Term Use
comparison of the two systems, featuring
both on and off-site regeneration, of deep
bed units for a once-through supercritical
unit with oxygenated treatment are
nearly twice as expensive as a precoat
system. Graver Water presented a
paper discussing this data at the annual
International Water Conference in
October, 2006.
Filters Trap Suspended Solids,
Have No Ion Exchange Capacity
T
wo types of filters are available
for CCGT condensate treatment:
disposable and backwashable.
Brian Raab, Graver Technologies’ Utility
Filters product manager, discussed this
technology choice.
Q: Is filtration a suitable standalone
technology for treating CCGT
condensate?
A: Filters, which trap suspended
contaminants such as copper and
iron oxides but don’t affect dissolved
contaminants, are cost-effective solutions
for short-term use and are better than no
condensate treatment at all. The filters
can provide significant improvements in
condensate quality. They’re affordable
and relatively easy to maintain. When
CCGTs had lower utilization rates,
filters made more sense. Today’s
heavier usage patterns and constant
cycling, however, demand precoat filter
demineralizers to better protect CCGT
assets, stabilize chemistry, control lifetime
costs and optimize operations. Plants
with air-cooled condensors, in particular,
need more than just filtration because
oxidation and degradation begin almost
immediately upon shutdown.
Q: What types of filters are available
for CCGT CP treatment?
A: Filters can be either disposable –
AEGIS® TurboGuard® Pre Filters, for
example – or backwashable, such
as AFA® Pleated Backwashable Filter
Elements. Installed in custom housing
manufactured by Graver Water,
TurboGuard filters exhibit very high
dirt-holding capacity before replacement
is required and low pressure drop at
specified flow rates. They’re available
in a variety of micron ratings and are
easily replaced by plant operators.
AEGIS® TurboGuard® Pre Filter
AFA filter elements require Powdex
housings and will last many years if
backwashed properly. However, if you’re
electing AFA filters, you can install a full
precoat demineralizer system without
much additional investment. That’s what
we recommend.
For more information about TurboGuard
and AEGIS AFA filters, please contact
your Graver representative. 
Deep Bed Ion
Exchange Systems:
Not Optimal for CCGT
CP Applications
Higher Maintenance, Less Resin
Flexibility
G
raver Water and Graver
Technologies have made great
strides in regenerable deep bed
ion exchange equipment and technology.
These systems are often ideal for CP at
fossil and nuclear facilities. However,
deep beds are rarely the right CP choice
at CCGTs for a number of reasons:
Thermax, Graver Water and Graver
Technologies recently collaborated
on a state-of-the-art CP
pre filtration system for Areva Solar’s
125 MW concentrated solar plant
in Pokharan, India. A twin plant is
slated for 2014.
System cost is high: Ongoing deep
bed system costs include regenerant
chemicals as well as the cost of disposal
– precoat filter demineralizer systems use
no regenerants. Further, an economic
High level of operator attention required:
Maintaining deep bed ion exchange
systems requires regular application
of regenerant chemicals, disposal
management, periodic resin replacement
and system adjustment. The manpower
for this maintenance is rarely in place
at CCGTs.
Resin composition is difficult to modify:
Replacing resin products in precoat
filter demineralizers is a simple process
entailing backwashing the precoat septa
and preparing a new resin precoat from
easy to handle bags. Should condensate
chemistry and/or composition change,
Graver designs tailored resin mixes
that are easily inserted into the system.
Conversely, a deep bed system does
not offer similar flexibility.
Precoat demineralizers exhibit
comparable performance to deep bed
ion exchange in CCGT applications:
Rarely, CCGT condensors experience
problems that flood condensate with
high levels of dissolved solids that
would be more easily handled by deep
bed systems. Though not desirable,
precoat demineralizer systems can
handle this situation by precoating on
a very compressed schedule. In sum,
these issues are rare and do not offset
the many disadvantages of deep bed
systems for these applications.
Bead resins used in deep beds degrade
under extended contact with elevated
condensate temperatures: For plants
with air-cooled condensors – an
increasingly popular CCGT design
element – high condensate temperatures
can prematurely degrade anion
exchange resins in deep bed systems,
compromising functional capacity. 
Powerline | 3
Nanodex™ Filter
Papers for Nuclear
Customers: Tested
and Qualified
Nanodex Tracks System
and Plant Performance by
Monitoring Radionuclide and
Corrosion Products
G
raver’s patented Nanodex™ Ion
Exchange Filter Papers perform
diverse quantitative analyses in
nuclear applications including monitoring
corrosion products, measuring activity
levels and satisfying fuel warranty
requirements. Below we continue our
Q&A discussion of AX 100 anion and
CX 200 cation filter paper types. This
is the fourth such article; three previous
discussions appeared in Powerline’s
Spring 2012, Fall 2012 and Spring
2013 issues, reviewing filter disk
characteristics, types, applications and
more. These issues of Powerline are
located on Graver’s website for further
reference.
Q: What improvements do Nanodex
papers offer over competing filter
paper types?
A: They offer improved performance
while retaining the benefits of the
commercial ion exchange filter disks that
many U.S. nuclear plants are accustomed
to using. Nanodex filter papers feature
patented fibrillated nanofibers that
enhance the resins’ ability to remove
soluble species from aqueous feed
and effluent streams. These nanofibers
are loaded with finely subdivided ion
exchange resin media, increasing the
number of ion exchange sites and
allowing very accurate quantifications
of ionic species at low activity or
concentration levels.
At the same time, Nanodex filter papers
are easy and safe to handle, fit standard
bench-top or in-line filter holdings and
housings of 47-mm diameter, and offer
good durability and stability.
Please contact your Graver representative
for more information about Nanodex Ion
Exchange Filter Papers. 
Sales & Services
UNITED STATES
Graver Technologies, LLC
200 Lake Drive
Glasgow, DE 19702
P (800) 533.6623
P (302) 731.1700
F (302) 731.1707
E [email protected]
Wwww.gravertech.com
Anand Harohalli
Director Business Development
P (302) 731.3543
C (302) 319.0353
[email protected]
Seth Kaufman
Regional Manager NW/Canada
P (704) 854.3422
C (704) 904.5168
[email protected]
Charlie Mosser
Technical Service Manager
P (817) 326.3626
C (817) 233.9358
[email protected]
Wayne Norwood
Regional Manager Southeast
P (301) 953.7731
C (301) 332.7934
[email protected]
Brian Raab
Utility Filter Product Manager
P (302) 731.3512
C (443) 907.9113
[email protected]
Gil Royal
Utility Sales Manager, North America
P (302) 731.3554
C (302) 668.4163
[email protected]
Al Tavares
Ion Exchange Product Manager
P (973) 690.5290 ext 2370
C (201) 787.3696
[email protected]
Maureen Vollinger
Global Customer Service/Inside Sales
P (302) 731.3516
P (800) 533.6623
F (302) 369.8356
[email protected]
Dr. Peter Yarnell
Ion Exchange Development
Group Leader
P (302) 731.3529
C (302) 731.1707
[email protected]
Mark Koster
President, International Utilities
Division
P (302) 731.3513
C (302) 463.5896
[email protected]
CHINA
Graver Technologies, LLC
RM 16D, Building B
No.1118, Changshou Road
Shanghai, China 200042
P (86) 21.5238.6576.608
F (86) 21.5238.6579
Xiaoyun Huang
Regional Sales Manager
C (86) 186.2800.1300
[email protected]
Xiaoyun Li
Customer Service
P (86) 21.5238.6576
F (86) 21.5238.6579
C (86) 139.1896.1206
[email protected]
Qingyuan Liu
Regional Sales Engineer
C (86) 136.2371.4398
[email protected]
Pei Tao
Sales Representative
C (86) 187.2174.7242
[email protected]
Xiangdong Xu
Regional Sales Manager
C (86) 139.1058.0025
[email protected]
Erbao Zhang
Chief Representative
C (86) 137.0188.2885
[email protected]
EUROPE
Graver Technologies, LLC
Koenigstrasse, 10c
D-70173 Stuttgart, Germany
P (49) 711.3154.7160
C (33) 6.19.33.11.10
F (49) 711.3154.7170
Robert Schiedlbauer
European Sales Manager
P (49) 711.3154.7160
C (33) 6.19.33.11.10
[email protected]
All information and recommendations appearing in this newsletter concerning the use of products described herein are
based on tests believed to be reliable. However, it is the user’s responsibility to determine the suitability for his own use
of such products. Since the actual use by others is beyond our control, no guarantee, expressed or implied, is made by
Graver Technologies as to the effects of such use or the results to be obtained. Graver Technologies assumes no liability
arising out of the use by others of such products. Nor is the information herein to be construed as absolutely complete,
since additional information may be necessary or desirable when particular or exceptional conditions or circumstances
exist or because of applicable laws or government regulations. Powdex, Ecodex, Aegis, TurboGuard, AFA, PowerGuard,
and Powerline are registered trademarks, and Nanodex is a trademark of Graver Technologies.
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